My worst paranoia is receiving mail. Official letters are bad, ones without a return address I often don't open at all. As far as I'm concerned, if they don't care enough to tell me who sent the mail, then I don't care enough to open it.
And the rare personnel hand written letter scares the hell out of me. Why are they writing to me? What did I do? I have all these random abuses running through my mind. It takes effort to calm myself down and open the letter, to find it's just my mom telling me about there holidays.